The present invention relates to a process for the production of a styrene compound, and a styrene compound free from biphenyl. More particularly, the present invention relates to a process for the production of a styrene compound which comprises reacting a Grignard reagent prepared from an aromatic halogen compound with a vinyl halide in the presence of a catalyst, and styrene compound free from biphenyl.
A styrene derivative towards which the present invention is directed is very useful as a raw material of functional high molecular compounds, medicines, agricultural chemicals, etc. For example, para-tertiary butoxystyrene (hereinafter referred to as xe2x80x9cPTBSxe2x80x9d) is known to be extremely useful as a raw material of a resist for use in super LSI""s, etc. (JP-A-59-199705 (The term xe2x80x9cJP-Axe2x80x9d as used herein means an xe2x80x9cunexamined published Japanese patent applicationxe2x80x9d), JP-A-3-277608). Further, meta-tertiary butoxystyrene (hereinafter referred to as xe2x80x9cMTBSxe2x80x9d) is known to be useful as an intermediate raw material of functional high molecular compounds, medicines, agricultural chemicals, etc. (JP-A-2-160739).
Two processes for the production of a styrene derivative such as PTBS and MTBS have been heretofore known.
U.S. Pat. No. 4,603,101 and JP-A-59-199705 disclose a process involving the reaction of a Grignard reagent prepared from halostyrene with perbenzoic acid tertiary butyl ester. However, this production process gives a low reaction yield. In addition, this production process is disadvantageous in that it requires the use of a perbenzoic acid tertiary butyl ester, which is difficult to be available in a large amount and is explosive. Thus, this production process leaves something to be desired in mass production of a styrene derivative such as PTBS and MTBS.
On the other hand, JP-B-4-71896 (The term xe2x80x9cJP-Axe2x80x9d as used herein means an xe2x80x9cunexamined published Japanese patent applicationxe2x80x9d) and JP-A-2-160739 disclose a process involving the reaction of a Grignard reagent prepared from a tertiary butoxyphenyl halide with a vinyl halide in the presence of a nickel-phosphine complex catalyst. However, this production process is disadvantageous in that it requires the use of a nickel-phosphine complex catalyst which is expensive and very toxic, although providing some improvement in reaction yield. The above cited patent applications describe that bidentate phosphine complexes such as dichloro[1, 2-bis (diphenylphosphino)ethane]nickel and dichloro[1, 3-bis (diphenylphosphino)propane] nickel are effective for the progress of this reaction in a high yield. However, these catalysts are expensive and very toxic. Accordingly, even if this production process is used, it is difficult to produce a styrene derivative such as PTBS and MTBS economically and safely. Thus, this production process, too, leaves something to be desired in mass production of a styrene derivative such as PTBS and MTBS.
Further, the present inventors have found that in the case of producing tertiary-butoxystyrene by those processes, biphenyl is produced as a reaction by-product. Biphenyl has the characteristic of having strong absorption to far ultraviolet light of excimer laser or the like used in super LSI. For this reason, if biphenyl is present in a resist resin, there are the problems that the presence decreases light permeability and also decreases resolution of a resist, thus inducing unfavorable trouble. In other words, it is preferable for tertiary-butoxystyrene used in resist to not contain biphenyl as an impurity. However, boiling points of tertiary-butoxystyrene and biphenyl are very close, and thus it is extremely difficult to remove biphenyl once produced, by general distillation operation.
It is therefore an object of the present invention to provide a process for the production of a styrene compound giving improvements over the prior art, and a styrene compound free from biphenyl. More particularly, the object of the present invention is to provide a process for the production of a styrene compound such as PTBS and MTBS which gives solution to the prior art problems and hence provides excellent economy and safety, and also provide a high quality tertiary butoxystyrene free from biphenyl.
The above object of the present invention will become more apparent from the following detailed description and examples.
The inventors made extensive studies of solution to the prior art problems. As a result, it was found that the use of a specific catalyst in a process for the production of a styrene compound such as PTBS and MTBS involving the reaction of a Grignard reagent prepared from tertiary butoxyphenyl halide with a vinyl halide in the presence of a catalyst makes it possible to produce such a styrene compound economically and safely on an industrial basis. It was further found that using this catalytic process makes it possible to achieve a reaction which does not form biphenyl by-product at all. Thus, the present invention has been worked out.
That is, the present invention provides a process for the production of a styrene compound which comprises reacting a Grignard reagent prepared from a tertiary butoxyphenyl halide represented by the following formula (I): 
wherein X represents a halogen atom, with a vinyl halide in the presence of a catalyst, wherein said catalyst is at least one member selected from the group consisting of a manganese catalyst, an iron catalyst, a cobalt catalyst and a rhodium catalyst.
The present invention also provides a styrene compound free from biphenyl, obtained using this process.
The present invention will be further described with reference to the production of PTBS.
The Grignard reagent to be used in the production process of the present invention is not specifically limited so far as it is prepared from an aromatic halogen compound. Thus, the Grignard reagent of the present invention can be easily prepared by any ordinary method. In other words, the Grignard reagent of the present invention can be easily prepared, e.g., by a process which comprises the reaction of metallic magnesium with para-tertiary butoxyphenyl halide in a solvent. If activated metallic magnesium is used in this preparation process, particularly good results can be given. Examples of effective methods for activating metallic magnesium include a method involving heating of a suspension of metallic magnesium in a solvent with stirring and a method involving stirring of such a suspension mixed with a slight amount of iodine, iodide such as methyl iodide, bromide such as dibromoethane or the like.
In accordance with the production process of the present invention, the reaction of a Grignard reagent prepared by the above method with a vinyl halide in the presence of one or more catalysts selected from the group consisting of manganese catalyst, iron catalyst, cobalt catalyst and rhodium catalyst makes it possible to produce PTBS safely in a high yield at a low cost.
Examples of the vinyl halide used in the production process of the present invention include vinyl fluoride, vinyl chloride, vinyl bromide, and vinyl iodide. These vinyl halides may be used singly or in admixture. In general, vinyl chloride gas and/or vinyl bromide gas are selected taking into account the economy and availability.
The catalyst used herein comprises one or more catalysts selected from the group consisting of manganese catalyst, iron catalyst, cobalt catalyst and rhodium catalyst.
The term xe2x80x9cmanganese catalystxe2x80x9d as used herein means to indicate a catalyst comprising manganese element as an effective component. Thus, the manganese catalyst used herein is not specifically limited. In practice, however, manganese powder, manganese compounds such as manganese chloride (II), manganese bromide (II), manganese iodide (II), manganese fluoride (II), manganese acetate (II), manganese acetate (III), manganese formate (II), manganese oxalate (II), manganese benzoate (II), manganese stearate (II), manganese borate (II), manganese acetylacetonate (II), manganese acetylacetonate (III), manganese carbonate (II), manganese sulfate (II), manganese nitrate (II) and manganese phosphate (II), hydrates thereof, various complex catalysts derived from these compounds, etc. may be used.
The term xe2x80x9ciron catalystxe2x80x9d as used herein means to indicate a catalyst comprising iron element as an effective component. Thus, the iron catalyst used herein is not specifically limited. In practice, however, ferrous halide, ferric halide, catalyst prepared from ferrous halide, catalyst prepared from ferric halide, etc. may be used.
The term xe2x80x9ccatalyst prepared from ferrous halidexe2x80x9d as used herein means to indicate a catalyst derived from ferrous halide or a catalyst comprising ferrous halide as an effective component. Examples of such a catalyst include hydrates and various complex catalysts of ferrous halide.
The term xe2x80x9ccatalyst prepared from ferric halidexe2x80x9d as used herein can be similarly defined. Examples of such a catalyst include hydrates and various complex catalysts of ferric halide.
Specific examples of the iron catalyst used in the production process of the present invention include iron powder, iron compounds such as ferrous chloride (II), ferric chloride (III), ferrous bromide (II), ferric bromide (III), ferrous iodide (II), ferrous fluoride (II), ferric fluoride (III), ferrous acetate (II), ferrous oxalate (II), ferric oxalate (III), ferric citrate (III), ferric perchlorate (III), ferric acetylacetonate (III), ferric nitrate (III), ferric phosphate (III), ferrous sulfate (II) and ferrous sulfate (II), hydrates thereof, and various complex catalysts derived from these compounds.
The term xe2x80x9ccobalt catalystxe2x80x9d as used herein means to indicate a catalyst comprising cobalt element as an effective component. Thus, the cobalt catalyst used herein is not specifically limited. In practice, however, cobalt powder, cobalt compounds such as cobalt chloride (II), cobalt bromide (II), cobalt iodide (II), cobalt fluoride (II), cobalt acetate (II), cobalt acetate (III), cobalt formate (II), cobalt oxalate (II), cobalt benzoate (II), cobalt stearate (II), cobalt borate (II), cobalt acetylacetonate (II), cobalt acetylacetonate (III), cobalt carbonate (II), cobalt sulfate (II), cobalt nitrate (II) and cobalt phosphate (II), hydrates thereof, various complex catalysts derived from these compounds, etc. may be used.
The term xe2x80x9crhodium catalystxe2x80x9d as used herein means to indicate a catalyst comprising rhodium element as an effective component. Thus, the rhodium catalyst used herein is not specifically limited. In practice, however, rhodium powder, rhodium compounds such as rhodium-carbon, rhodium chloride (II), rhodium bromide (II), rhodium acetate (II), rhodium acetate (III), rhodium acetylacetonate (II) and rhodium acetylacetonate (III), hydrates thereof, various complex catalysts derived from these compounds, etc. may be used.
In the production process of the present invention, the above catalysts may be used singly or in admixture. If one or more catalysts selected from the group consisting of manganese halide, manganese acetate, iron halide, iron acetate, cobalt halide, cobalt acetate, rhodium halide and rhodium acetate are used, particularly good results (high yield) can be given. The amount of the catalyst to be used in the production process of the present invention is not specifically limited. In general, however, it is from about 10xe2x88x924 to 101 mols per mole of the Grignard reagent used.
The foregoing prior art production process (as disclosed in JP-B-4-71896) is disadvantageous in that it requires the use of a nickel-phosphine complex catalyst which is expensive and very toxic. Further, this production process has the problem that biphenyl which is unfavorable impurity is by-produced, and thus was not satisfactory as and industrial production of PTBS. The inventors found for the first time that one or more catalysts selected from the group consisting of manganese catalyst, iron catalyst, cobalt catalyst and rhodium catalyst, which are inexpensive and safe, are effective for the reaction of a Grignard reagent prepared from para-tertiary butoxyphenyl halide with a vinyl halide. Among these catalysts, one or more catalysts selected from the group consisting of manganese halide, manganese acetate, iron halide, iron acetate, cobalt halide, cobalt acetate, rhodium acetate are very inexpensive and safe catalysts. The production process of the present invention using such a catalyst is extremely useful for the industrial production of PTBS.
The production process of the present invention is normally effected in a solvent in the presence of an inert gas atmosphere such as nitrogen and argon. Examples of the reaction solvent used in the production process of the present invention include ether solvent, oxygen-containing solvent, nitrogen-containing solvent, aromatic hydrocarbon solvent, and aliphatic hydrocarbon solvent. In general, these solvents may be used singly or in admixture. In particular, if tetrahydrofuran or a mixed solvent containing tetrahydrofuran is used, good results (high yield) can be given. The production process of the present invention is normally effected at a temperature of from 0xc2x0 C. to the reflux temperature of the solvent used.
After completion of the reaction, the reaction solution is treated with an acidic aqueous solution by an ordinary method to cause the separation of an organic phase. Subsequently, the organic phase is rinsed, and then subjected to distillation to remove the solvent therefrom. A polymerization inhibitor such as tertiary butyl catechol is added to the reaction solution which is then subjected to distillation to obtain desired PTBS.
The production process of the present invention is not limited to the above production of PTBS but can find wide application in the same reaction for the production of styrene derivatives from aromatic halogen compounds. If applied to the production of a tertiary butoxystyrene such as PTBS and MTBS, the production process of the present invention can provide particularly good results (high yield).
The term xe2x80x9caromatic halogen compoundxe2x80x9d as used herein is a general term for compounds substituted by halogen at least one position in aromatic ring.
The aromatic halogen compound used in the present invention is preferably a tertiary butoxyphenyl halide represented by the following formula (I): 
Wherein X represents a halogen atom.
Examples of the aromatic halogen compounds employable herein include benzene fluoride derivatives, chlorinated benzene derivatives, brominated benzene derivatives, and iodinated benzene derivatives.
As mentioned above, the production process of the present invention not only can give solution to the prior art problems and hence can produce a styrene derivative economically and safely on an industrial basis, but also enables a reaction which does not form biphenyl by-product al all.
The present invention will be further described in the following examples, but the present invention should not be construed as being limited thereto.